Splice for a heat shrinkable label

ABSTRACT

A structure is defined for supplying heat shrinkable labels to a labeling machine. Two elongated webs of a heat shrinkable laminate are provided having a continuous series of printed labels positioned end to end thereon. A clear heat shrinkable splice, having an adhesive on one surface, is used to secure the ends of the two webs such that they are positioned adjacent one another and such that they form a single continuous web. The material of the labels and the material of the splice have substantially equivalent shrinkage values such that, upon application of heat to the label and splice within the label machine, the label shrinks along with the splice without causing substantial distortion to the printing on the label. Because the splice is clear or transparent, it can be positioned on the outside of the label, over the printing without obliterating same.

[0001] This is a continuation of co-pending application Ser. No.09/064,258, filed Apr. 23, 1998, now abandoned.

FIELD OF THE INVENTION

[0002] Heat shrinkable labels are commonly used for packaging andcontainers, e.g., soda bottles and other round containers. The labelsare typically printed end to end on an elongated web which is wound on aroll or spool. One edge of the web is first glued on to the side wall ofthe container and then the label is wrapped around the circumference ofthe container. The label is then cut from the roll and the resultingedge is glued on to the container such that the two edges overlap. Asufficient amount of slack is provided in the label to accommodate theheat shrink qualities of the material. When heat is applied, the labelmaterial shrinks and conforms to the surface contours of the container.An example of such a labeling operation is identified in Hoffmann U.S.Pat. No. 4,406,721, which is herein incorporated by reference.

[0003] It is desirable to operate the labeling machine on a continuousbasis. For this reason, a new supply of labels must be presented afterthe end of each roll. Typically, the end of one roll of labels isautomatically spliced to the beginning of a second or following roll,creating a continuous web.

[0004] In the past, the splice material has been applied to the outsideof the label web, over the printing on the label. The splice is brightlycolored so as to stand out on the container as it is conveyed towardsthe final packaging equipment. A quality control person is required tomonitor the labeled containers to visually locate containers thatinclude a spliced label and remove those containers from the line priorto packaging and shipment to a customer. The splices have to be placedon the outside of the label so that the quality control person can seethe splice on the label. If the splice were placed under the label, thecoloring of the label could obscure the splice, resulting in a splicedlabel being shipped.

[0005] Since the labeled containers are usually fed on a conveyor to apackaging location, there is sometimes a tendency for the product toturn or spin around on the conveyor such that the splice is not facingthe quality control person as the container passes. In these situations,a container with a spliced label may be missed and the container shippedto a customer. For this purpose, a fallout flag is often attached to thelabel at the splice so that the container having the splice is moreeasily identifiable for removal purposes. Even with this addedprecaution, containers with spliced labels are shipped much of the time.

[0006] The prior spliced labels are considered unacceptable for mostapplications because the labels tend to cover a portion of the text ormarketing materials on the label. The splices also disfigure the labeldue to the contrasting brightly colored splice. Moreover, conventionalsplices are typically made from materials which are non-shrinkable. Assuch, when the spliced label is heat-shrunk onto a container, the splicedistorts the label.

SUMMARY OF THE INVENTION

[0007] The present invention relates to a structure for joining abuttingends of two webs of elongated heat shrinkable label material. The twowebs are aligned end to end and a splice composed of a heat shrinkablematerial adheres the two ends together, thereby connecting the two websto form a single continuous web. When the spliced label is attached toand wrapped around a container, the splice shrinks along with the labelwithout distorting, splitting or causing excess fatigue within the labelmaterial. In addition, preferably, the splice material is clear ortransparent so that the printing on the label is not defaced. Further,the splice may be applied to the inside surfaces of the two abuttinglabel webs; thus, when the label is heat shrunk onto the container, thesplice is positioned below the label and is covered thereby.

[0008] The present invention can be used in a labeling machine forjoining together two or more webs from separate rolls to form acontinuous feed of label material to the machine. Alternately, thepresent invention can be used to join a series of webs together to forma single roll or spool of label material. The spliced roll of labelmaterial can then be used with a conventional labeling machine to applythe spliced labels to products.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] For the purpose of illustrating the invention, there is shown inthe drawings a form which is presently preferred; it being understood,however, that this invention is not limited to the precise arrangementsand instrumentalities shown.

[0010]FIG. 1 is an isometric view of a container with a labelsurrounding the perimeter of the container, the label including a heatshrinkable splice as contemplated by the present invention.

[0011]FIG. 2 is an isometric view of abutting ends of two label rollsconnected by the shrinkable splice of the present invention.

[0012]FIG. 3 is a partial cross sectional view of a container having theheat shrinkable label and splice combination as contemplated by thepresent invention and as taken along line 3-3 in FIG. 1.

[0013]FIG. 4 is a partial cross sectional view of the container, heatshrinkable label and splice combination as taken along line 4-4 in FIG.1.

DETAILED DESCRIPTION OF THE DRAWINGS

[0014] In the drawings, where like numerals identify like elements,there is shown a container which is generally referred to by the numeral10. In FIG. 1, the container 10 is a generally cylindrical can which iscontemplated to have a removable lid or cap. The container 10 has a heatshrunk label 12 thereon. The label 12 is formed such that the edge 14wraps over the top edge of the container 10. In addition, a series ofperforations 16 are provided such that the top portion of the label 12may be separated from the bottom portion when the lid of the container10 is unscrewed from the base of the container. As illustrated inphantom in FIG. 1, a splice 18 is provided under the label for joiningtwo ends 20, 22 of label material.

[0015] The formation of the splice 18 is more particularly illustratedin FIG. 2. The edges of the two ends 20, 22 of label material arepositioned in an abutting relationship. Alternatively, there may be someoverlap and the edges may be tacked or glued to one another. The splice18 is positioned over the joint between the two ends of materials 20, 22and is secured thereto by an adhesive 24 which is preferably formed onthe rear surface of the splice material. The splice 18 secures the twoends 20, 22 of the label material and permits the attachment of thelabel material to the container in the manner described above.

[0016] After the label 12 is heat shrunk onto the container 10, thesplice 18 is located inside of the label, underneath the ends 20, 22 ofthe abutting edges of the two rolls of material. Alternatively, thesplice could be positioned over the printing (not shown) on the label 12and, when the label material is wrapped around the container, positionedon the outside of the label. For this reason, the splice material ispreferably clear or transparent so that the printing is not obliterated.A transparent splice also matches transparent labels, whether on theinside of the outside of the butt joint.

[0017] Another aspect of the invention is the use of a heat shrinkablematerial for the splice 18. This material will preferably have shrinkcharacteristics that are similar (if not exact) to that of the labelmaterial. This shrink rate is preferably compatible in both thelongitudinal and lateral directions of the label material. A typicallabel material will be bidirectional in that it will have a greatershrink rate in the longitudinal direction (see arrow 26 in FIG. 2) thanin the lateral direction (arrow 28 in FIG. 2). The splice will be formedsuch that it is positioned transverse to the label. The longitudinal orlengthwise shrink rate of the splice will be preferably the same orsimilar to that of the lateral (28) shrink rate of the label material.Similarly, the shrink rate of the splice in its lateral or widthwisedirection will be similar to that in the longitudinal (26) direction ofthe label. These properties for the splice will create relatively evenshrinkage of the label when the heat is applied, and thus limit orprevent distortion of the printing on the label and/or tearing,splitting or fatiguing due to irregular shrinkage of the two materials.As can be seen in FIGS. 3 and 4, the label 12 and the splice 18 conformto the contours of the sidewall 30 of the container 10. Because thesplice also shrinks with the label, the conformance is relatively thesame at the splice as it would be where the label material alone coversthe contour.

[0018] Another contemplated feature of the present invention is theadhesive used in conjunction with the splice as well as the tearstrength of the splice material. Typically, the splice is formed on aroll with adhesive on one surface thereof and a release liner coveringthe adhesive. In order for the operation of the label machine to besubstantially continuous, the splice must be created quickly. Thisrequires the splice material to be unrolled from the roll, removed fromthe release liner, and adhered to the abutting edges of the labelmaterial at a relatively high rate of speed. Sufficient tensile strengthmust be provided in the lengthwise direction of the splice material.Also, the adhesive must have sufficient release qualities to permit thisremoval from the roll without undue resistance.

[0019] The splice material and adhesive must have sufficient strength tosecure the two ends of the label material together as it is pulled intothe labeling machine and as it is applied to the container. Also, theadhesive must be able to withstand the heat applied to the label andsplice during shrinking of the label onto the container. If the adhesivewere to degrade excessively under heat or tension, the splice couldbecome undone. Further, the adhesive must allow the splice and label toshrink. It is contemplated that the relative rate of shrinkage may notbe the same (i.e., one may shrink at a greater rate), although theoverall shrinkage percentage may be compatible in the final condition(i.e., when the two reach final condition, they have shrunk relativelythe same amount).

[0020] With these parameters in mind, certain materials have beenidentified to create the combined heat shrinkable label and splice ascontemplated by the present invention. The label material may be ashrinkable polypropylene film such as Vision® 370C or 345C from AETPackaging Film of Wilmington, DE. Alternatively, the label may be madefrom a laminate of the 370C film in conjunction with a Vision® 370W typefilm with a two part urethane coating. Other commercial shrinkablelabels or materials are also known and may be utilized for the presentinvention.

[0021] The material of the splice is preferably a clear, flexible, highshrinkage film with an aggressive adhesive coating. The aggressiveadhesive is preferably selected to have a high range of tack (based ontesting according to ASTM D 2979-71) between about 300 gm/cm² and about600 gm/cm². Preferably, the aggressive adhesive has a tack of about 450gm/cm². A top coat on the film layer may be included if the splice is tohave printing or coloring disposed on it.

[0022] One suitable splice material that is available on the market isSECUREcal™ EXPE-400-FC Shrink which is manufactured by the FlexconCompany, Inc. This material includes a polyethylene film layer with aTC-391 top coating, a V-23 adhesive and is provided on a 44 PP-8 polycoated natural kraft release liner. The V-23 adhesive is a permanentpressure sensitive acrylic adhesive with a tack within the abovepreferred ranges. The adhesive layer is about 1.0 to 1.1 mils thick. Thefilm layer is approximately 4 mils thick. The liner is about 3.1 milsthick. This material has the desired relative shrink ratios and has beenfound through testing to be compatible with the label materialsidentified above, and for this reason is presently preferred. Theadhesive is capable of withstanding the stresses exerted on the adhesiveby the heat shrinking of the abutted labels. The adhesive also resistsdegradation.

[0023] An another splice material which can be used in the presentinvention is SECUREcal™ DEV-200-C Shrink which is also manufactured bythe Flexcon Company, Inc. This splice material includes a clear vinylfilm layer with a TC-248 top coating, a V-23 adhesive and a 44 PP-8 polycoated natural Kraft release liner. The adhesive layer is about 1.0 to1.1 mils thick. The film layer is approximately 2 mils thick. The lineris about 3.1 mils thick.

[0024] Based on the teachings provided herein, persons skilled in theart would be readily capable of substituting other types of splicematerial for the above preferred materials.

[0025] While the present invention has been described as applicable forsplicing two rolls of label material together, it is also contemplatedthat the present invention can be used to attach multiple webs of labelmaterial together to form a single roll. In this embodiment, the presentinvention would be used by a label manufacturer to splice a series ofwebs of label material together. The spliced label material would thenbe wound onto a roll for subsequent use in a labeling machine.

[0026] As with conventional splices for attaching multiple rolls inlabeling machines, conventional splices for attaching multiple webs on asingle roll must be brightly colored. The bright coloring of theconventional splice permits the splice to be visually detected so thatthe splice can be skipped prior to application to a product, or aproduct which contains the splice can be removed by the operator priorto shipment. The present invention addresses this problem withconventional systems by using a transparent heat-shrinkable splice toform a roll of continuous label material from a series of shorter labelwebs.

[0027] The present invention solves the problems of the prior artsystems by eliminating the need to detect splices within a label. As aresult, the present invention greatly increases the productionefficiency of a labeling process.

[0028] The present invention may be embodied in other specific formswithout departing from the spirit or essential attributes thereof and,accordingly, reference should be made to the appended claims, ratherthan to the foregoing specification, as indicating the scope of theinvention.

What is claimed is:
 1. A structure for joining abutting ends of two websof labels, each web having two ends, the structure comprising: a splicemember for overlapping the abutting ends of the two label webs, thesplice member comprising a heat shrinkable material; and an adhesivecoating on a surface of the splice member for securing the splice memberto the two ends of the label webs.
 2. The structure according to claim1, wherein the heat shrinkable material of the splice member istransparent.
 3. The structure according to claim 1, wherein the heatshrinkable material of the splice member comprises a polyethylene film.4. The structure according to claim 1, wherein the label webs are fromtwo separate label rolls.
 5. A structure for supplying heat shrinkablelabels to a labeling machine comprising: (a) at least two elongated websof a heat shrinkable laminate, each web provided with a continuousseries of printed labels thereon, the labels positioned end to end alongeach web, each web having a leading end and a trailing end; and (b) aclear heat shrinkable splice tape, the splice tape having a top and abottom surface, an adhesive on the bottom surface of the splice tape,the adhesive adhering the splice tape to the leading end of one web andto the trailing end of another web such that they form a continuous web,the laminate material of the webs and the material of the splice tapehaving substantially equivalent shrinkage rates such that, uponapplication of heat to a label and splice tape within the labelingmachine, the label shrinks along with the splice tape without causingsubstantial distortion to the printing on the label.
 6. The structureaccording to claim 5 wherein the splice tape is adhered to the ends ofthe webs over the printing thereon.
 7. The structure according to claim5 wherein the laminate material of the webs comprises a polypropylenefilm.
 8. A structure as claimed in claim 5, wherein each of the webscomprises a laminate of two plies of polypropylene film.
 9. Thestructure according to claim 5 wherein the material of the splice tapecomprises a polyethylene film.
 10. A structure as claimed in claim 9wherein each of the webs comprises a laminate of a polypropylene film.11. The structure according to claim 5 wherein each web is provided on aseparate roll.
 12. A method for joining ends of two webs of labels eachhaving a leading end and a trailing end to form a continuous web,comprising the steps of: a. providing first and second webs of heatshrinkable label material; b. providing a splice tape having at leastone layer of a heat shrinkable material defining a surface and a coatingof adhesive on the surface; c. aligning the trailing end of the firstweb with the leading end of the second web such that the ends abut oneanother; d. adhering the splice tape to the aligned ends of the two websso as to form a continuous web.
 13. The method according to claim 12,wherein the at least one layer of the splice tape is transparent. 14.The method according to claim 12, wherein the label material of each ofthe webs comprises: a. a first laminate of heat shrinkable material; b.an adhesive in contact with the first laminate; c. ink in contact withthe adhesive; and d. a second laminate of heat shrinkable material incontact with said ink, the first and second laminates havingsubstantially equivalent shrinkage rates.
 15. The method according toclaim 14, wherein the material of the splice tape has a substantiallyequivalent shrinkage rate as the first and second laminate of the webs.16. The method according to claim 12 wherein each web is provided on aseparate roll.
 17. The method according to claim 12 further comprisingthe step of winding the continuous web onto a roll.
 18. A containerhaving sidewalls, a top surface and a bottom surface, comprising: a heatshrinkable label having first and second segments wrapped around theperiphery of the container, and each label segment having a first andsecond end and an inside and outside surface, the first end of the firstlabel segment secured to the sidewall of the container, the first labelsegment wrapped around a first portion of the periphery of thecontainer, the second end of the first label segment juxtaposed to andaligned with the first end of the second label segment; and a splicetape having at least one layer of a heat shrinkable material and a layerof an adhesive, the adhesive layer of the splice tape joining thejuxtaposed and aligned ends of the first and second label segments, thesecond label segment wrapped around a second portion of the containerperiphery, the second end of the second label segment secured to thefirst end of the first label segment, wherein the splice tape and labelhave been heat shrunk onto the container.
 19. The container according toclaim 18 wherein the splice tape is positioned on the outside surface ofthe label segments.
 20. The container according to claim 18 wherein thesplice tape is positioned on the inner surfaces of the label segments.21. A splice tape for joining abutting ends of two webs of heatshrinkable labels, each web having two ends, the splice tape comprising:at least one layer of a heat shrinkable material for overlapping theabutting ends of the two label webs; and an adhesive layer for securingthe splice tape to the two ends of the label webs.
 22. A supply of heatshrinkable labels for a labeling machine comprising: (a) at least twoelongated webs of a heat shrinkable laminate, each web having alongitudinal length and a lateral width and a continuous series ofprinted labels thereon, the labels positioned end to end along thelength of each web, each web having a leading end and a trailing end;and (b) a splice tape having a longitudinal length and a lateral widthand comprising at least one layer of a heat shrinkable material defininga surface, the splice tape further comprising an adhesive coating on thesurface of the at least one layer of heat shrinkable material, thesplice tape extending transversely with respect to the length of thewebs, the splice tape adhered to the leading end of one web and to thetrailing end of another web such that the webs form a continuous web.23. The heat shrinkable label supply according to claim 23 wherein thewebs and the splice tape have longitudinal and lateral shrinkage rates,the longitudinal shrinkage rate of the splice tape begin substantiallyequal to the lateral shrinkage rate of the webs and the lateralshrinkage rate of the splice tape being substantially equal to thelongitudinal shrinkage rate of the webs such that, upon application ofheat to the splice tape and a label from the continuous web, distortionto the printing on the label caused by differential shrinkage betweenthe splice tape and the label will be substantially limited.